This invention relates to fluid injection apparatus for feeding a plurality of different additive fluids to equipment in which the fluids are used. For example, the present apparatus may be employed to deliver to a laundry system or dishwashing unit different liquid detergents, soaps, water softeners, bleaches, or other additive liquids or solutions.
In prior equipment of this general type, problems have been encountered because of the tendency for some of the additive fluids from a particular operation of the equipment to remain in the injection pump and related valves which control delivery of the fluids to the equipment of use, and cause clogging of the pump which decreases its effectiveness on the next successive operation. Further, the chemicals which thus remain in the injection system mix with and contaminate whatever fluids may be selected for injection in the next cycle of operation, and result in incorrect application of additives to the equipment of use, and a resultant adverse effect on the overall result attained by that equipment.